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Genus CHAULELASMUS. 



Anas apud Linnaeus, Syst. Nat. i. p. 200 (1766). 

 Ktinorhynchus apud Eyton, Monogr. Anat. p. 137 (1838). 

 Chaulodus apud Swainson, Journ. Roy. Inst. ii. p. 19 (1839). 

 Chaulelasmus, G. R. Gray, Gen. of B. iii. p. 617 (1845). 

 Querquedula apud Macgillivray, Man. Brit. B. ii. p. 169 (1840). 



Although in many respects the Gadwall, which is the sole representative of this genus, resembles 

 the Mallard, yet the peculiarity in the lamellae of the bill renders it very distinct from the birds 

 belonging to the genus Anas, as well as from other allied genera. As stated in the article on this 

 species, the Gadwall inhabits the Palsearctic, Nearctic, and Ethiopian Regions ; and full par- 

 ticulars as to its habits and nidification are there given. 



Chaulelasmus streperus, the type of the genus, has the bill rather shorter than the head, 

 about as high as broad at the base, the culmen gradually sloping nearly to the end, the bill 

 slightly broader near the tip than at the base, and rounded at the tip ; unguis broadly oval, 

 decurved ; gape-line slightly curved, the ends of the lamella?, which are fine and deep, showing 

 clearly along the edge of the bill ; trachea with the tube enlarged near the lower extremity, but 

 contracted above the inferior larynx, which has a medium-sized osseous bulb extending on one 

 side and much anteriorly ; wings moderate, pointed, the first two quills longest, inner secondaries 

 and scapulars elongated, pointed ; legs and feet as in Anas, but rather more slender ; plumage 

 close, full, the feathers on the crown and nape rather long and full. 



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